Mount Maunganui's Cody Cooper in form at US motocross Nationals

Cody Cooper has made a great start in the US. Photo / File

Mount Maunganui's Cody Cooper has produced a top-10 performance early in his US Nationals motocross campaign.

The former New Zealand champ finished 10th overall in Saturday's second round of the Lucas Oil AMA Pro Motocross Championship raced at Glen Helen Raceway near San Bernardino, California.

Cooper qualified 15th quickest in a 52-strong field for the premier MX450 class on his Honda and in both races, he advanced through the pack after bad starts.

From 25th at the first corner of the opening moto Cooper moved up to finish in 16th position.

He didn't have as far to climb in the second moto with a 15th place start and he ran as high as eighth place mid-race before finishing 10th. Cooper has now moved up to 12th in the MX450 championship standings after two rounds.

"I got bad starts in both motos but Glen Helen was okay with 10th overall," Cooper said.

"I just feel like I could have been better than 16th in first moto. I didn't get much riding in the week before Glen Helen as I have had a sore elbow. We're heading east this week to race Colorado next weekend."

Kawasaki rider Eli Tomac won both motos and is unbeaten after two rounds with a 14-point lead over Frenchman Marvin Musquin (KTM).

Round three also brings the challenge of altitude as riders contest the Thunder Valley National at Lakewood, Colorado this weekend.